Abstract: In order to further understand the long-term performance of fiber reinforced polymer composites (FRP) under different exposure circumstances, a new degradation model, based on existing durability of experimental data and analysis of the scale parameter η and the shape parameter β, is proposed to describe long-term deterioration of FRP characteristics by using two-parameter Weibull distributions. Based on the result, the scale parameter η of tensile strength is found to decrease significantly with increasing time, and the decline is faster in the early stage of degradation; and the shape factor β is insensitive to different exporsure circumstances. The prediction of probabilistic model are compared with experimental durability data and characteristics value, and the results indicate that the proposed model can well predict the long-term characteristics of FRP. Finally, the environment reduction factor κ_env is suggested, which serves as important reference in strengthening design.

Key words: fiber reinforced polymer, two-parameter Weibull probability distribution, durability, degradation model, environment reduction factor